An ancient river could see the light of day again, thanks to a collapsing tramline in the centre of the Greek capital Athens.

The Ilisos emerges overground

Years of lax maintenance and natural erosion have left the route in such a poor state that trams stopped running last October, but this very modern problem could also turn into an historic opportunity.

The River Ilisos was mentioned by Plato, and saw philosophers from Socrates to the Cynics teach on its banks.

'Crimes of Athens'

But it was paved over as part of the post-war urban development drive, in what the Kathimerini daily called "one of the many crimes that took place in Athens in the name of progress".

The 1950s saw the rapid development of Athens

It now runs in a tunnel under Vasileos Konstantinou and Kallirois Avenues, only to emerge briefly in a thicket behind the Temple of Olympia Zeus, where local enthusiasts have long been trying to clear space to show it off to better advantage

But all this may be about to change.

Professor Nikos Belavilas heads Athens Anaplasis, a Greek government company charged with rejuvenating the city's urban fabric, and he has a plan to avoid "spending tens of millions of euros on repairing the tunnel, when we could bring the river to the surface for a lot less money instead".

The river Ilisos emerges briefly in reed beds behind the Temple of Olympian Zeus

He proposes to create a broad band of parkland on both banks of the newly-exposed river, running south from the Panathenaic Stadium - home of the revived 1896 Olympic Games - for 1.2 km (0.7 miles).

Professor Belavilas, who teaches urban planning at the School of Architecture of the National Technical University of Athens and is director of its Urban Environment Laboratory, says the idea, which he first floated in November, is now a firm plan that has won some "important allies", Ethnos newspaper reports.

'Doesn't bear thinking about'

The Athens transport and water companies are on board with the scheme, which will involve re-routing the tramlines to create a direct pedestrian route from the Temple of Olympian Zeus to the National Gardens.

This route has been long-cherished by Athenians, but fell foul first of planning for the 2004 Summer Olympics, and then the 2008 financial crisis, Kathimerini recalls.

Much of the river was still above ground until the 1960s

But it is not just a simple matter of reclaiming the city's past, but also of saving its present."If the Ilisos tunnel collapses, it will block the natural course of the river, and could flood the entire city centre," Mr Belavilas warns - "That doesn't bear thinking about."